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weight and performance calculations for the Handley Page H.P.81 Hermes IV
Handley Page H.P.81 Hermes IV
role : commuter prop airliner
importance : **
first flight : Hermes IV G-AKFP 5 September 1948 operational : August 1950
country : United-Kingdom
design :
production : Mk.IV 25 aircraft
general information :
Development alongside the Handley Page Hastings military transport for the RAF.
G-AGSS H.P.68 prototype crashed during first flight shortly after take-off on 2 December 1945. It is believed that the aircraft had encountered severe longitudinal instability due to elevator overbalance. Handley Page's chief test pilot and the chief test observer were both killed in the incident, while the prototype was completely destroyed by a post-impact fire. It had 1650 hp Bristol Hercules 101engines
G-AGUB H.P.74 Hermes II prototype with 4.57 [m] longer fuselage made it’s first flight 02 September 1947. It still had a tail-wheel landing gear. 1675 hp Hercules 121 engines. 1 H.P.74 was built.
Max landing weight : 34019 kg
Fuel capacity : 3224 imp. gallon (14657 litres) oil capacity : 4 x 37 imp gallon (total 672 litres). BOAC flew a few years with the Hermes, then they were sold to smaller airlines who used them for charter flights.
primary users : BOAC, Airwork Ltd. London, Air Safaris, Skyways of London, Britavia
registrations : H.P.68 G-AGSS H.P.74 G-AGUB H.P.81 G-AKFP, G-ALDH, G-ALDM,
G-ALDU, G-ALDA, G-ALDN, G-ALDW, G-ALDK, G-ALDJ, G-ALDV, G-ALDC
flight crew : 4 cabin crew : 3 passengers : 63
flight crew consist of pilot, co-pilot, radio operator and engineer
powerplant : 4 Bristol Hercules 763 air-cooled 14 -cylinder radial engine 1775 [hp]
(1323.6 KW) normal rating, supercharged engine, high blower, constant power to height
: 4000 [m] and with 2100 [hp](1566.0 KW) available for take-off
dimensions :
wingspan : 34.44 [m], length : 29.51 [m], height : 9.12 [m]
wing area : 130.8 [m^2]
weights :
max.take-off weight : 39009 [kg]
empty weight operational : 25106 [kg] useful load : 8122 [kg]
performance :
maximum continuous speed : 544 [km/u] op 4000 [m]
normal cruise speed : 441 [km/u] op 6100 [m] (53 [%] power)
service ceiling : 7500 [m]
range with max fuel : 5022 [km] and allowance for 457.5 [km] diversion and 30 [min]
hold
description :
low-winged monoplane with retractable landing gear with nose wheel
tapered multi-cellular wing with flush-riveted stressed skin
with Fowler flaps airfoil : root : NACA 23021 tip : NACA 23007
engines and landing gear attached to the wings, fuel tanks in the wings
construction : all-metal aluminium-alloy stressed-skin construction with pressurized fuselage
fuselage shape : O
airscrew :
four De Havilland Hydromatic constant speed, fully-feathering 4 -bladed tractor
airscrews
max. efficiency :0.74 [ ]
diameter airscrew 4.00 [m]
relative pitch (J) : 1.84 [ ]
power loading prop : 165.45 [KW/m]
G-AKFP first Hermes IV, made it’s first flight 5 September 1948
theoretical pitch without slip : 8.19 [m]
blade angle prop at max.speed : 41.99 [ ]
tip-speed close to speed of sound (above Mach 0.85) > loose of efficiency
reduction : 0.44 [ ]
airscrew revs : 1232 [r.p.m.]
aerodynamic pitch at max. continuous speed 7.36 [m]
blade-tip speed at max.continuous speed : 299 [m/s]
propellor noise in flight : 103 [Db]
calculation : *1* (dimensions)
measured wing chord : 3.98 [m] at 50% wingspan
mean wing chord : 3.80 [m]
calculated average wing chord tapered wing with rounded tips: 3.69 [m]
wing aspect ratio : 9.1 []
seize (span*length*height) : 9269 [m^3]
calculation : *2* (fuel consumption)
oil consumption : 58.2 [kg/hr]
fuel consumption (econ. cruise speed) : 831.2 [kg/hr] (1133.9 [litre/hr]) at 53 [%] power
distance flown for 1 kg fuel : 0.53 [km/kg] at 6100 [m] height, sfc : 295.0 [kg/kwh]
estimated total fuel capacity : 14656 [litre] (10743 [kg])
calculation : *3* (weight)
weight engine(s) dry with reduction gear : 3576.0 [kg] = 0.68 [kg/KW]
weight 1018.9 litre oil tank : 86.60 [kg]
oil tank filled with 39.7 litre oil : 35.6 [kg]
oil in engine 29.5 litre oil : 26.5 [kg]
fuel in engine 36.1 litre fuel : 26.47 [kg]
weight 482.1 litre gravity patrol tank(s) : 72.3 [kg]
weight jet stacks : 132.4 [kg]
weight NACA cowling 59.3 [kg]
weight variable pitch control : 34.5 [kg]
weight airscrew(s) incl. boss & bolts : 971.6 [kg]
total weight propulsion system : 4987 [kg](12.8 [%])
***************************************************************
fuselage aluminium frame : 5457 [kg]
typical cabin layout for 63 passengers : pitch : 81 [cm] ( 2+2 ) seating in 15.8 rows
pax density (normal seating) : 0.84 [m2/pax]
high density seating passengers : 75 at 4 -abreast seating in 18.8 rows
weight 2 toilets : 19.0 [kg]
weight 5 hand fire extinguisher : 15 [kg]
weight buffet : 130.6 [kg]
weight 34 windows : 30.2 [kg]
weight 4 emergency exits : 12.0 [kg]
weight 3 life rafts : 78.8 [kg]
weight oxygen masks & oxygen generators : 41.0 [kg]
weight emergency flare installation : 10 [kg]
weight emergency evacuation slide : 15 [kg]
weight 2 entrance/exit doors : 24.0 [kg]
weight 2 freight doors (belly) : 8.0 [kg]
weight ladies" powder room : 16 [kg]
weight men"s dressing room : 12 [kg]
weight diplomatic mail locker : 2 [kg]
extra main deck space for freight/mail/luggage etc. : 1.19 [m3]
cabin volume (usable), excluding flight deck : 105.71 [m3]
passenger cabin max.width : 2.85 [m] cabin length : 18.55 [m] cabin height : 2.36 [m]
pressure at cruise height 6100.00 [m] : 0.47 [kg/cm2] cabin pressure : 0.77 [kg/cm2]
weight rear pressure bulkhead : 146.2 [kg]
weight air pressurization system : 31.2 [kg]
fuselage covering ( 188.4 [m2] duraluminium 3.86 [mm]) : 1904.4 [kg]
weight floor beams : 100.1 [kg]
weight cabin furbishing : 332.9 [kg]
weight cabin floor : 297.7 [kg]
fuselage (sound proof) isolation : 84.7 [kg]
weight radio transceiver equipment : 7.0 [kg]
weight radio direction finding (RDF) equipment : 5.0 [kg]
weight artificial horizon : 1.1 [kg]
weight instruments. : 13.0 [kg]
weight APU / engine starter: 66.2 [kg]
weight lighting : 15.8 [kg]
weight electricity generator : 15.8 [kg]
weight controls : 13.2 [kg]
weight seats : 350.0 [kg]
weight air conditioning : 94 [kg]
total weight fuselage : 9216 [kg](23.6 [%])
***************************************************************
total weight aluminium ribs (525 ribs) : 1391 [kg]
weight engine mounts : 265 [kg]
weight fuel tanks empty for total 14174 [litre] fuel : 1134 [kg]
weight wing covering (painted aluminium 2.77 [mm]) : 1955 [kg]
total weight aluminium spars (multi-cellular wing structure) : 2153 [kg]
weight wings : 5499 [kg]
weight wing/square meter : 42.04 [kg]
cantilever wing without bracing cables
weight rubber de-icing boots : 37.9 [kg]
weight fin & rudder (13.8 [m2]) : 580.9 [kg]
weight stabilizer & elevator (14.7 [m2]): 619.6 [kg]
weight flight control hydraulic servo actuators: 38.7 [kg]
weight fowler flaps (10.9 [m2]) : 235.1 [kg]
total weight wing surfaces & bracing : 8410 [kg] (21.6 [%])
*******************************************************************
wheel pressure : 9752.2 [kg]
weight 4 Dunlop main wheels (1250 [mm] by 192 [mm]) : 875.7 [kg]
weight nose wheel : 109.5 [kg]
weight hydraulic wheel-brakes : 33.2 [kg]
weight pneumatic-hydraulic shock absorbers : 44.3 [kg]
weight wheel hydraulic operated retraction system : 126.7 [kg]
weight undercarriage struts with axle 679.8 [kg]
total weight landing gear : 1900.3 [kg] (4.9 [%]
*******************************************************************
********************************************************************
calculated empty weight : 24513 [kg](62.8 [%])
weight oil for 13.7 hours flying : 795.9 [kg]
calculated operational weight empty : 25309 [kg] (64.9 [%])
published operational weight empty : 25106 [kg] (64.4 [%])
weight crew : 567 [kg]
weight fuel for 2.0 hours flying : 1662 [kg]
weight catering : 251.1 [kg]
weight water : 200.9 [kg]
********************************************************************
operational weight empty: 27990 [kg](71.8 [%])
weight 63 passengers : 4851 [kg]
weight luggage : 769 [kg]
weight cargo : 2502 [kg]
operational weight loaded: 36112 [kg](92.6 [%])
fuel reserve : 2896.9 [kg] enough for 3.49 [hours] flying
operational weight fully loaded : 39009 [kg] with fuel tank filled for 42 [%]
published maximum take-off weight : 39009 [kg] (100.0 [%])
calculation : * 4 * (engine power)
power loading (Take-off) : 6.23 [kg/kW]
power loading (operational without useful load) : 5.29 [kg/kW]
power loading (Take-off) 1 PUF: 8.30 [kg/kW]
max.total take-off power : 6263.9 [kW]
calculation : *5* (loads)
manoeuvre load : 3.3 [g] at 1000 [m]
limit load : 3.0 [g] ultimate load : 4.5 [g] load factor : 1.7 [g]
design flight time : 7.97 [hours]
design cycles : 4568 sorties, design hours : 36410 [hours]
operational wing loading : 2776 [N/m^2]
wing stress (3 g) during operation : 198 [N/kg] at 3g emergency manoeuvre
calculation : *6* (angles of attack)
angle of attack zero lift : -1.35 ["]
max. angle of attack (stalling angle, clean) : 11.45 ["]
max. angle of attack (full flaps) : 10.56 ["]
angle of attack at max. speed : 1.18 ["]
calculation : *7* (lift & drag ratios
lift coefficient at angle of attack 0° : 0.12 [ ]
lift coefficient at max. speed : 0.22 [ ]
lift coefficient at max. angle of attack : 1.13 [ ]
max.lift coefficient full flaps : 1.56 [ ]
induced drag coefficient at max.speed : 0.0023 [ ]
drag coefficient at max. speed : 0.0203 [ ]
drag coefficient (zero lift) : 0.0180 [ ]
calculation : *8* (speeds
stalling speed at sea-level (OW loaded : 38178 [kg]): 231 [km/u]
stalling speed at sea-level with full flaps (normal landing weight): 158 [km/u]
landing speed at sea-level (normal landing weight : 35030 [kg]): 181 [km/hr]
max. rate of climb speed : 235 [km/hr] at sea-level
max. endurance speed : 228 [km/u] min.fuel/hr : 548 [kg/hr] at height : 610 [m]
max. range speed : 399 [km/u] min. fuel consumption : 2.081 [kg/km] at cruise height :
6096 [m]
cruising speed : 441 [km/hr] at 6100 [m] (power:60 [%])
max. continuous speed* : 544.00 [km/hr] at 4000 [m] (power:100 [%])
climbing speed at sea-level (loaded) : 413 [m/min]
climbing speed at 1000 [m] with 1 engine out (PUF / MTOW) : 258 [m/min]
climbing speed at 1000 [m] with 2 engines out (2xPUF / MTOW) : 62 [m/min]
calculation : *9* (regarding various performances)
take-off speed : 256.6 [km/u]
emergency/TO power : 2100 [hp] at 2800 [rpm]
static prop wash : 174 [km/u]
high wheel pressure, can only take off from paved runways
take-off distance at sea-level concrete runway : 1030 [m]
take-off distance at sea-level over 15 [m] height : 1172 [m]
landing run : 641 [m]
landing run from 15 [m] : 1281 [m]
lift/drag ratio : 17.49 [ ]
climb to 1000m with max payload : 2.93 [min]
climb to 2000m with max payload : 5.98 [min]
climb to 3000m with max payload : 9.17 [min]
climb to 5000 [m] with max payload : 19.24 [min]
practical ceiling (operational weight empty 27990 [kg] ) : 8900 [m]
practical ceiling fully loaded (mtow- 30 min.fuel:38593 [kg] ) : 6900 [m]
calculation *10* (action radius & endurance)
published range : 5022 [km] with 7 crew and 2680.2 [kg] useful load and 97.3 [%] fuel
(no reserves)
range : 2408 [km] with 7 crew and 8122.0 [kg] useful load and 46.6 [%] fuel
range : 3610 [km] with 63.0 passengers with each 12.2 [kg] luggage and 69.9 [%] fuel
Available Seat Kilometres (ASK) : 227417 [paskm]
max range theoretically with additional fuel tanks total 18580.1 [litre] fuel : 6543 [km]
useful load with range 500km : 12578 [kg]
useful load with range 500km : 63 passengers
production (theor.max load): 5547 [tonkm/hour]
production (useful load): 3582 [tonkm/hour]
production (passengers): 27783 [paskm/hour]
G-ALDC suffered this “pretty”mishap when it returned from a charter flight (Barcelona). It suffered aquaplaning while landing at its destination at Southend. The Hermes IV overran the runway ending on this railway track.
combi aircraft mail/freight/passengers
oil and fuel consumption per tonkm : 0.160 [kg]
fuel cost per paskm : 0.032 [eur]
crew cost per paskm : 0.032 [eur]
economic hours : 18250 [hours] is less then design hours
time between engine failure : 1205 [hr]
can continue fly on 3 engines, low risk for emergency landing for PUF
writing off per paskm : 0.040 [eur]
insurance per paskm : 0.0003 [eur]
maintenance cost per paskm : 0.141 [eur]
direct operating cost per paskm : 0.246 [eur]
direct operating cost per tonkm (max. load): 1.231 [eur]
direct operating cost per tonkm (normal useful load): 1.906 [eur]
Literature :
Piston-engined airliners page 61
Verkeersvliegtuigen Moussault page 35,112
Wikipedia
Jane’s fighting aircraft WWII page 124
Handley Page HP.81 Hermes IV: A truly well connected destination. | Aviation Rapture (wordpress.com)
Picture of Handley Page Hastings Military Transport Aircraft and information (airpowerworld.info)
Handley Page H.P.81 Hermes - civil transport (aviastar.org)
* max. continuous speed : max. level speed maintainable for minimal 30 min.
Handley Page Hastings, military transport, 147 were built for the RAF
DISCLAIMER Above calculations are based on published data, they must be
regarded as indication not as facts.
Calculated performance and weight may not correspond with actual weights
and performances and are assumptions for which no responsibility can be taken.
Calculations are as accurate as possible, they can be fine-tuned when more data
is available, you are welcome to give suggestions and additional information
so we can improve our program. For copyright on drawings/photographs/
content please mail to below mail address
G-ALEU H.P.82 Hermes V with 2490 hp Bristol Theseus 502 turboprops. First flight August 1949.
(c) B van der Zalm 03 April 2022 contact : info.aircraftinvestigation@gmail.com python 3.7.4